A circuit board which is accommodated in a mobile terminal such as a mobile telephone comprises a substrate on which a circuit pattern is formed, and plural electronic components which are mounted on the substrate by fixing terminal portions to the circuit pattern through solder.
Recently, a circuit board is proposed in which the mounting strength of an electronic component is improved by a resin portion (underfill) that covers a part of the body of the electronic component, and that is in close contact with a substrate (see Patent Reference 1).
Patent Reference 1 can be applied also to the case where the mounting strength is improved by a resin portion that collectively covers the whole of plural electronic components mounted on a substrate.
Patent Reference 1: Japanese Patent No. 3,241,669